78512500 has 72 divisors (see below), whose sum is σ = 187675488. Its totient is φ = 28500000.

The previous prime is 78512461. The next prime is 78512509. The reversal of 78512500 is 521587.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78512509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 137215 + ... + 137785.

It is an arithmetic number, because the mean of its divisors is an integer number (2606604).

Almost surely, 2^78512500 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78512500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93837744).

78512500 is an abundant number, since it is smaller than the sum of its proper divisors (109162988).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78512500 is a wasteful number, since it uses less digits than its factorization.

78512500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 611 (or 589 counting only the distinct ones).

The product of its (nonzero) digits is 2800, while the sum is 28.

The square root of 78512500 is about 8860.7279610651. The cubic root of 78512500 is about 428.1996113770.

It can be divided in two parts, 78 and 512500, that added together give a triangular number (512578 = T₁₀₁₂).

The spelling of 78512500 in words is "seventy-eight million, five hundred twelve thousand, five hundred".